Help Please

[Dan C]

Wouldn't surprise me if its been sitting in the sump for a while. I found a lump of alloy about the size of a sixpence in my 450 sump when I recommissioned it. It was about the same size as the hole in the piston from the mid 1990's......I can only surmise that the bloke who repaired the holed piston didn't go looking for the missing bit......

Cheers Dan

[Duccout]

Thanks everyone. The pieces measure 3.3mm x 12mm and I would say that they are definitely from the upper bevel 1202 bearing, certainly the pieces are identical to a bearing that I have here for comparison, unless there is another double row bearing somewhere else. When I worked on the bike when I acquired it I found that one or both of the lower bevel bearing cages were damaged, so maybe the debris from the top caused that on its way through?

Colin.

[Duccout]

After thinking about this I believe that the pieces of top bearing cage made their way down the bevel tube and through the two oil drain channels at the rear of the lower bevel housing, and then from there into the timing chest and into the sump. I think that the balls stayed in place between the two races until a previous owner discovered the problem and fitted a new bearing. I don't know if the cage breaking up is common with the rivetted cage, but there is a You Tube video of an American racer with a 450 that has suffered the same problem.

I am just about to refill the sump with Smith and Allan 15/50 fully synthetic.

Colin